One of the major difficulties in paleontology is the acquisition of fossil data from the 10% of Earth's terrestrial surface that is covered by thick glaciers and ice sheets. Here we reveal that DNA and amino acids from buried organisms can be recovered from the basal sections of deep ice cores and allow reconstructions of past flora and fauna. We show that high altitude southern Greenland, currently lying below more than two kilometers of ice, was once inhabited by a diverse array of conifer trees and insects that may date back more than 450 thousand years. The results provide the first direct evidence in support of a forested southern Greenland and suggest that many deep ice cores may contain genetic records of paleoenvironments in their basal sections.The environmental histories of high latitude regions such as Greenland and Antarctica are poorly understood because much of the fossil evidence is hidden below kilometer thick ice sheets (1-3). Here, we test the idea that the basal sections of deep ice cores can act as archives for ancient biomolecules and show that these molecules can be used to reconstruct significant parts of the past plant and animal life in currently ice covered areas.The samples studied come from the basal impurity rich (silty) ice sections of the 2km long Dye 3 core from south-central Greenland (4), the 3km long GRIP core from the summit of the UKPMC Funders Group Author Manuscript UKPMC Funders Group Author ManuscriptGreenland ice sheet (5), and the Late Holocene John Evans Glacier on Ellesmere Island, Nunavut, northern Canada (Fig. 1A,B). The latter sample was included as a control to test for potential exotic DNA because the glacier has recently overridden a land surface with a known vegetation cover (6). As an additional test for long-distance atmospheric dispersal of DNA, we included five control samples of debris-free Holocene and Pleistocene ice taken just above the basal silty samples from the Dye 3 and GRIP ice cores (Fig. 1B). Finally, our analyses included sediment samples from the Kap København Formation from the northernmost part of Greenland, dated to 2.4 million years before present (Ma BP) (1,2).The silty ice yielded only few pollen grains and no macrofossils (7). However, the Dye 3 and John Evans Glacier silty ice samples showed low levels of amino acid racemization (Fig. 1A, insert), indicating good organic matter preservation (8). Therefore, following previous success with permafrost and cave sediments (9-11), we attempted to amplify ancient DNA from the ice. This was done following strict criteria to secure authenticity (12-14), including covering the surface of the frozen cores with plasmid DNA to control for potential contamination that may have entered the interior of the samples through cracks or during the sampling procedure (7). PCR products of the plasmid DNA were obtained only from extracts of the outer ice scrapings but not from the interior, confirming that sample contamination had not penetrated the cores.We could reproducibly PCR amplify short ampli...

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Ice cores drilled from glaciers around the world generally contain horizons with elevated levels of beta radioactivity including 36Cl and 3H associated with atmospheric thermonuclear bomb testing in the 1950s and 1960s. Ice cores collected in 2006 from Naimona'nyi Glacier in the Himalaya (Tibet) lack these distinctive marker horizons suggesting no net accumulation of mass (ice) since at least 1950. Naimona'nyi is the highest glacier (6050 masl) documented to be losing mass annually suggesting the possibility of similar mass loss on other high‐elevation glaciers in low and mid‐latitudes under a warmer Earth scenario. If climatic conditions dominating the mass balance of Naimona'nyi extend to other glaciers in the region, the implications for water resources could be serious as these glaciers feed the headwaters of the Indus, Ganges, and Brahmaputra Rivers that sustain one of the world's most populous regions.